It is known in the art to utilize development restrainers and development restrainer precursors in photographic applications. A predetermined level of development usually will take place before the development restrainers or development restrainer precursors function to inhibit or control further development. The blocked development restrainers are designed to provide a timed release of the development restrainer during the development process. Such blocked development restrainers are disclosed, for example, in U.S. Pat. Nos. 3,260,597 and 3,265,498 which disclose hydrolyzable blocked restrainers; U.S. Pat. No. 3,698,898 which discloses the use of quinone- or naphthoquinonemethide precursors which release a photographic reagent such as 1-phenyl-5-mercaptotetrazole in the presence of alkali; U.S. Pat. No. 4,009,029 which discloses a class of cyanoethyl-containing blocked development restrainers; and German Offenlegungsschrift No. 2,427,813 which discloses various blocked development restrainers.
The present application relates to novel compounds which are useful in photographic applications as well as photographic products and processes which utilize the compounds.